Slow internet on fast TX rate WiFi

What am I looking for by doing a double NAT?

To see if the issue has to do with routing.. by using a double NAT we put the TC into action as the main router..

But then we can also add a very simple test..

Download blackmagic disk test.. and check on the Mac with 2.4ghz the speed to copy files to the TC disk.. although I would not expect huge speed it should still exceed your internet speed by enough to prove where the problem lies.

Also is "scan plot" the "scan" window for wireless diagnostics with the channel numbers and such? What am I looking for in that after changing the NAT settings?

RSSI and actual interference levels.. the amount of wireless in your network.. the amount of wireless outside your network.

I would also be watching very carefully for link speeds during the black magic disk tests.

You will see that more clearly in the Performance window.

Overall we are still trying to confirm where is the problem.

The slow speed with FIOS on 2.4ghz really makes this confusing.. because that makes the problem the clients if they are all experiencing the same thing.. as it is unlikely that both the TC and FIOS are faulty.

We need to know which model it is??

Please look at the base unless it is tower one.. in which case just say tower.. for any of the flat models.. A1xxx or if you know which Gen the product is tell us that.

I turned on the wireless for Fios Router 2.4 and it’s still slow.

This is very pertinent to your question.

As long as the Time Capsule and the FIOS are on different channels I doubt you are going to experience any great interference problems at least from your own equipment.

Your high connection speed would also tend to indicate the issue is not wireless per se.

Although I doubt you will ever achieve 100Mbps over 2.4ghz you should easily get 60-70 and perhaps a bit more.

Let me suggest as a test you put the Time Capsule in double NAT.

You can turn off the wireless in the FIOS but I don't think that is any major issue.

The TC will kick up a double NAT error which you can just ignore for the moment.

Save the configuration of the TC if you like before you start.

Reset to factory.. and use all short names, no spaces pure alphanumerics. Passwords same rules.. but 8-20 characters.

Then use the wireless diagnostics in the Mac and show the scan plot.

I have the same problem with an early 2008 imac (802.11n) and a gigabit gateway from AT&T. At first the speeds were in the 50 to 60 Mbps range, and after a few days they dropped to 3 down and 10 up, more or less. The Tx rate, however, is typically from 30 to 100 or more and usually at least 50. Signal is in the -60s and noise in the -80s or -90s. The MCS is now 11 and moves around from about 5 to 13 or 14. Why the dramatic slowdown? Thanks for any help.

I think you can have a routing problem. The later airports do have some issues.

The main test I really want you to do is local lan speeds.. so we have a comparison.

I’m at the point where I’m thinking of just buying a Amplifi Mesh system so I can get 5Ghz everywhere.

Getting 5ghz signal all over the house is certainly helpful.

I use ethernet connected WAP at 3 or 4 points in the house. It is really superior to any mesh system. But it is more expensive to run the ethernet in the first place.

Signal is in the -60s and noise in the -80s or -90s. The MCS is now 11 and moves around from about 5 to 13 or 14. Why the dramatic slowdown?

To help we need to see the actual plots from wireless diagnostics.

It is also possible it is swapping from 2.4ghz to 5ghz and back again.. it would be well worth looking at.

But on a computer of that age.. I would just setup a wireless bridge.. and plug it into the computer by ethernet. The airport express can do this but there are much better (and cheaper) units readily available.

Thank you for reply, LaPastenague. It turns out that when I move the computer to a location a few feet from the gateway the speeds are what they should be (about 130/160) for 802.11n. Apparently the upstairs room must be right on the edge of a WiFi speed precipice, if such a thing exists. I don't know if speeds drop off gradually or in steps. I can't test with the iMac - too bulky. One weird thing - my work laptop, which has 802.11ac, also suffered from a 90 percent speed decrease. I took it downstairs and it was back to normal, and then moved it upstairs and it is back to normal there. There are several walls in the path and about a dozen networks nearby (nearly all on different 2.4 GH channels), which may be the cause of the irregular WiFi performance. I think the optimum solution is to run a Cat6 cable through the walls and attic from a jack next to the gateway to a jack in the computer/office room, connect the gateway to the jack downstairs, connect a switch into the upstairs jack, and connect both computers to the switch. Does that make sense?

I think the optimum solution is to run a Cat6 cable through the walls and attic from a jack next to the gateway to a jack in the computer/office room, connect the gateway to the jack downstairs, connect a switch into the upstairs jack, and connect both computers to the switch. Does that make sense?

This is what we continually recommend to people. Wireless is great on your portable devices.. but short distance to the AP if you want high speed. And ethernet backbone around the house. And for desktop computers with ethernet then definitely use ethernet. Even laptops if you need to buy a thunderbolt to ethernet adapter it is a good buy to have reliable internet.

In your upstairs area you can use another Airport Extreme or any WAP or wireless router. It is more expensive than just a switch but gives you wireless closer to where you might need it for other things.. and you can use the extra ports on the Extreme etc for your computer.